Dear glass coat requires more after care. It is not a miracle solution as it sounds, you need to be more careful with it.
I sparingly use water. Mostly I clean my car once a week with waterless solution spray and it takes just 300 mls to do the entire car.
Only use Karcher when it is super dirty or after rain. Karcher uses less water compared to a hose pipe.
Only go to service station in case car has been driven in rains on muddy and flooded roads.
Waxing periodically is better and cost effective solution in my opinion